Carbon pile regulator



Dec. 5, 1950 w. c. NEILD 2,533,038

CARBON FILE REGULATOR Filed April 1, 1948 2 Sheets-Sheet 1 IN V EN TOR.

Dec. 5, 1950 w. e. NEILD 2,533,038

CARBON PILE REGULATOR Filed A ril 1; 1948 2 Sheets-Sheet 2 1N VEN TOR.

Patented Dec. 5, 1950 CARBON PILE REGULATOR William G. Neild, Warren Point, N. J assignor to Bendix Aviation Corporation, Tcterboro, N. J., a corporation of-Delaware Application April 1, 1948,-Serial No. 18,433

6 Claims. 1

The present application relates to improvements in a carbon pile regulator of the type dis-' closed in the cO-pending U, S. application Serial No. 684,379, filed July 17, 1946,- by WilliamGr. Neild, now Patent No; 2,506,234, dated May 2, 1950.

An object of the invention is to provideanovel temperature compensator'for a carbon pile.

Another object of the invention i to provide a temperature compensating'means mounted interiorly of the carbon pile for correcting for change with temperature in the length of the carbon pile.

Another object of the invention is to provide an improved armature spring arrangement.

Another object of the invention is to provide an improvement in the mountin 'of the armature spring for the carbon pile, including a novel ball and socket arrangement for operatively connectin the armature and spring.

Another object of the invention is to'provide improved adjustment means for the armature springto Vary the spring characteristic thereof to match the force of the electromagnet;

Another object of the invention is to provide an improvement in the armature spring arrangement in which there is included 'a novel leaf spring so arranged as toassure that a movable carbon pile contact button follows the armature upon" movement thereof without the use of complicated linkages. Another object of theinvention is to provide an improvedhousing 'for the carbon pile; including a novel arrangement for shielding a voltage calibrating device, while permitting th ready adjustment thereof.

Another object of the invention is to provide a novel-and compact arrangement for a carbon pile regulator in which all adjustable-parts are enclosed to prevent tampering by unauthorized personnel.

The above and other objects and features of the invention will appear more fully hereinafter from a consideration of the following descriptiontakenin connection withthe accompanying drawings whereintwo embodiment ofthe. inventionare illustrated by way of example.

In the drawings:

Figure 1 is a longitudinal regulator.

Figure 2 is a fragmentary view. of the armature spring and mountingarrangement.

Figure 3 is a fragmentary view of a modified form of the spring arrangement.

Figure 4 is an end view-of the regulator houssectional view of the in showing the novel voltage adjustment and voltmeter test jacks provided therein.

Referring to the drawing of Figure 1, a carbon pile is illustrated at 10 and comprises a numberofhollow discs of carbon which are stacked within a tube H. The tube II is preferably formed of a suitable ceramic electrical insulating material to carry away the heat developed by the carbon pile Ill. The carbon pile i is of a suitable size and length to develop the desired regulating characteristics. The tube H is received within a metal shell 12 and, in order to facilitate the dissipation of the heat, the shell is preferably provided with fins l3 over its length so as to more readily dissipate the heat away from the pile and increase the capacity of the pile.

Contact elements 14 and I are adjustably mounted within the tube H at the opposite ends of the carbon pile H1. The contact element I 4 fits loosely in the tube I l and has mounted thereon a button 16 which bears upon an engaging element H of an armature 18 for regulation of the carbon pile It, as will be explained hereinafter.

Affixed at one end to the contact element I5 is a tubular member 20 formed of a material such as copper having a relatively high temperature coefficient of expansion. The tubular member 29 projects interiorly within the hollow carbon discs l0 and has secured to its other end by a pin 22 one end of a rod 24 formed of a material having a low temperature coefficient of expansion such as Invar. The opposite end of the rod 24 is connected by a pin 25 to a screw adjustably mounted in a plate 30.

The plate is fastened to the shell [2 by bolts 32 which are suitably insulated by member 34 from the plate 36. The plate 30 is also insulated from the shell 12 by a suitable insulating strip 36.

Through the latter arrangement, it will be seen that upon an increase in temperature tending to cause the pile is to lengthen, the tube 20 having a high temperature coefilcient of expansion will also'tend to lengthen relativeto the rod 24 causing the contact element [5 to move toward the-right so as to compensate for the lengthening of the pile due to such rise in ternperature.

A decrease in temperature will have the opposite effect on the tube 20 so that the tube will tend to move the contact element l5 toward the left to compensate for the temperature effect on the carbon pile l0.

It will be seen then that the tube projecting interiorly within the hollow carbon discs ID, the same will be directly responsive to the temperature of the carbon pile I6 so as to more accurately compensate for variations in the length of the pile due to change in temperature.

At theopposite end of the carbon pile ID the contact element I4 is regulated by action of the armature I8 so as to vary the compressive force applied on the carbon pile I8 and accordingly the resistance thereof. The armature I8 and spring assembly therefore may be of a type disclosed and claimed in the above mentioned patent.

As shown in Figure 1 the armature I8 includes a flexible metal hinge 38 which has one end riveted to the armature I8 and the other end fastened by bolt 49 and bar 42 to one end of a U-shaped supporting member 44 having legs which extend at opposite sides of an electromagnet 46. The electromagnet 46 is fastened by bolts 48 to a supporting plate 49. The bolts 48 also serve to secure the U-shaped member 44 to the plate 49. Screw threadedly engaged in the .plate' 49 is an adjustable electromagnetic core 50, which projects through the electromagnet 46 into operating spaced relation to the armature IS. The plate 49 is fastened to the shell I2 by rods 52,118 shown in Figure l. 7

While one end of the armature I8 is flexibly connected by the hinge member 38, the opposite end of the armature I8 is operatively connected to a spring mechanism indicated generally by the numeral 54 and shown in Figures 1 and 2.

The aforenoted mechanism includes a ball bearing 56 which rides at one side in a seat 58 carriedby the armature I8, while the opposite side of the ball bearing rides in a seat 60 formed in an adjustable member 62. has projecting therefrom a stem portion 64 having screw threads 66 which engage in corresponding internal threads formed in a member 68. A'lock nut I6 serves to fasten the screw .62 in adjusted position relative to the member blade I5 is similarly fastened to the supporting member 49 by like bolts indicated by the numeral 16. In operation it will be seen that upon a force being applied at the armature I8 by the The member 82 iii electromagnet 46, the spring blades will tend to Wrap or roll on the surface of the vertical member 68 and the horizontal member 49 as the armature I8 moves under the force of electromagnet 46. Such action will decrease the radius of the spring I5 and greatly increase its resistance to force, so as to provide a force deflection curve which very closely resembles an inverse square curve, and effect a rolling non-slipping action with a minimum friction. 7

The latter force deflection curve will closely approximate that of. the electromagnet 46 which will apply a force to the armature I8 which continuously increases in excess of a linear relation as the armature I8 approaches the electromagnet '46 and which force. will vary approximately inversely as the square of the distance between iii the armature and magnet. Thus, the opposing armature spring I6 is arranged to compensate for the varying force applied by the electromagnet 46 to the armature I8. Basic correspondence between the force of the spring I5 and the electromagnet 46 may be conveniently affected by adjusting the member 62 of the spring mechanism 64 and the core 56 of the magnet 46 so that the force of the one matches that of the other.

A modified form of the spring arrangement is shown in Figure 3 in which corresponding numerals indicate like parts to those described in Figure 2.

In the arrangement of Figure 3, the member 68 is split at 11 to provide leg portions I8 and I9 which have an inherent spring tension tending to bias the legs I8 and I9 inward. A wedgelike screw 80 is screw threadedly engaged in the split portion 71 of the member 68 for adjusting the leg portions I8 and I9 relative to the spring blades I5. The screw 80 has a cleft portion 82 readily accessible through an opening 84 in the plate 49 so that the screw 86 may be readily manually adjusted by means of a screw driver or other suitable tool.

The adjustment of the leg portions l8 and I9 relative to the spring blades 15 permits the force characteristic of the spring blades 15 to be varied so that the force deflection curve of the springs I5 may be matched more closely with the force of the electromagnet 46.

A further feature of the invention resides in the provision of a leaf spring 85 fastenedat opposite ends to the shell I2, as shown in Figure 2. Connected to the leaf spring 86 intermediate its opposite ends is the button I6. The leaf spring 85 biases the floating contact element I4 which is loosely positioned in tube II towards the armature I8. The armature I8 is spring hinged at 38 and biased by the spring mechanism 54 in a clockwise direction. The leaf spring 85 serves to keep the pile I0 together in the event the whole armature end should be removed and also centers the button I6 in relation to the member I! of the armature I8 without hand-fitting or complicated linkage.

A cover cap 86, shown in Figure 1, fits lightly about one end of the shell I2 and surrounds the armature spring assembly so as to protect the same from dust and possible injury. The cover cap 86 is fastened in position by a suitable screw 81.

At the opposite end of the shell I2 there is provided a bracket 90, as shown in Figure 1, fastened to the shell I2 by a nut 92 screw threadedly engaged on rod 52. Mounted in the bracket are jacks or electrical connectors 93 and an adjustable resistor 94 having a rotatable arm not shown which may be adjustably positioned on a resistor 88 by adjustment of a rotatable slotted head member I89. The variable resistor 94 has the variable resistance element 98 connected in series with the electromagnetic coil 46 so as to set the value of the electrical condition or voltage for which the coil 46 is to regulate. The jacks 93 are suitably connected across the regulated condition or voltage so that a voltmeter or other measuring instrument may be connected into the circuit through the jacks for testing purposes. A cover cap I82 is fastened to the bracket 96 by bolt I64. The cover cap I82 fits tightly about the latter end of the shell I2 and protects the calibrating resistor 94 from dust and possible damage. Suitable openings are formed in theendofthecoverlcaplfllso as to permit the ends of "the jacks 93 and the slotted head of theadjustable resistor 94-to project therethrough. Thecover cap feature isdisclosed and claimed in myzcopending divisional application Serial No. 121,115, filed October 13, 1949, and assigned to the assignee ofthe present application. L

This arrangement, which permits, only head 100; to be exposed,- is safe both electrically I and mechanically, In former units where the re-v sistor Bi-was. externally locatedthere was-proe vided fire hazards from :hot wiring,

The entire regulator assembly may beconveniently mountedon a base plate I which in turn'is' supported bysuitable shock mounts indicatedlgenerally -by thenumeral H0, as shown in Figure 4.

Suitable electrical conductors, not shown, lead from: one end of the carbon pile [0-, while another suitable electrical conductor leads from the other end of the carbon pile 10. These electrical conductors lead inturn to an insulated terminal board, not shown, which may be mounted in the base-platelBSso that the carbon pile may be conveniently connected into the-:regulating circuit as is well known in the art. Electrical conductors also lead from the terminal board to the electromagnet 46 through the calibrating resistor 94=sothatthe same .may be responsive to the regulated condition or voltage.

In the operationof thespring mechanism 54, in .the arrangement shown in Figures 1 and 2, it

will beseen that asthe armature I8 is drawn towards the electromagnetic coreBfl, the spring plates I5 will roll or wrap along the memberlifl and in toward the center on the horizontal member 48 and-therebydecrease the radius of the curve 15 and increase the resistance of the spring 15 to the magnet .force so as to effect basic correspondence with the non-linear force characteristic of the electromagnet 46.

Through the arrangement of the ball bearing 56 the element 62 may be conveniently rotated so astovary the tension of the springs 15 and thereby match the deflection curve of the spring 15' with that of the electromagnet 46. Through theadjustment screw'82 of Figure 3 the characteristic of the spring l5. may be varied so as tomore accurately balance or match the electromagnet 46.

It will be further seen that upon changes in temperature tending to vary the length of the pile the adjustment of the contact element l5 through the coaction of the tube 2%] and rod 24 will readily compensate for such changes in temperature.

Although only two embodiments of the invention have been illustrated and described, various changes in the form and relative arrangements of the parts may be made to suit requirements.

What is claimed is:

1. In an electrical regulator of the type including a variable electrical resistance means, an electromagnet, an armature movably mounted in relation to said electromagnet, means connecting the armature to the variable electrical resistance means, said electromagnet biasing said armature in a direction for changing the electrical resistance of said variable electrical resistance means; the improvement comprising a spring mechanism including a supporting member, a movable member operatively connected to said armature and extending at a substantially ninety degree angle to said supporting member, curved spring blades connected at opposite ends to said members and arranged so that upon movement of said armature toward said electromagnet said curved spring blades wrap upon said'supporting member and said movable member so as to decrease the radius of the curved blades and progressively increase the resistance of the spring blades to displacement of said armature by said electromagnet, said movable member including a pair of leg portions and a-wedge-like screw memberior adjusting-said leg portions to vary the force characteristicof the spring blades.

2. .In an electrical regulator of the type including a variable electrical resistance means, an electromagnet, an armature movably mounted in relationto said electromagnet, means connecting thearmatureto the variable'electrical resistance means, said electromagnet biasing said armature in a direction for changing the electrical resistance of said variable electrical resistance means; the improvement comprising a spring mechanism including a supporting member, a movable member, means to operatively connect said movable member tosaidarmature, said movable member extending at a substantially ninety degree angle to said supporting member, curved spring blades connected at opposite ends to said members and arranged so that upon movement of said armature toward said electromagnet said curved spring blades Wrap upon said supporting member. and said movable member so as tode-crease the radius of the curved blades and progressivel increase the resistance of the sprin blades to displace ment of said armature bysaid electromagnet, said connecting means including a ball bearing, a socket member for receiving said ball bearing, andsaid socket member rotatably adjustable for varying the length of. said connecting means to match the deflection force of the spring blades with that of the electromagnet.

3; In an electrical regulator of the type including a variable. electrical resistance means, an electromagnet, an armature movably mounted in relation to said electromagnet, means connecting the armature to the variable electrical resistance means, said electromagnet'biasing said armature in a direction for changing the electrical resistance of said variable electrical resistance means; the improvement comprising a spring mechanism including a supporting member, a movable member, means to operatively connect said movable member to said armature, said movable member extending at a substantially ninety degree angle to said supporting member, curved spring blades connected at opposite ends to said members and arranged so that upon movement of said armature toward said electromagnet said curved spring blades wrap upon said supporting member and said movable member so as to decrease the radius of the curved blades and progressively increase the resistance of the spring blades to displacement of said armature by said electromagnet, said connecting means including a ball bearing, a socket member for receiving said ball bearing, and said socket member rotatably adjustable for varying the length of said connecting means to vary the force of said spring blades, said movable member including a pair of leg portions and a Wedge-like adjustable screw member for positioning said leg portions to vary the force characteristic of the spring blades, and said electromagnet including an adjustable core member to vary the force characteristic of the electromagnet, said last three mentioned adjustable members being independently adjustable to match the 7 deflection force of the spring blades with that of the electromagnet.

4. An electrical regulator, comprising, in combination, a housing, a variable carbon pile resistance mounted in said housing, a first movable contact element in said housing at one end of the carbon pile resistance, a second movable contact element in said housing at the other end. of the carbon pile resistance, an electromagnet, an armature movably mounted in relation to said electromagnet, means operatively connecting the armature to said first contact element to vary the resistance of said carbon pile, temperature responsive means operatively connected to said secand movable contact element to compensate the carbon pile for changes in temperature, said temperature responsive means including a tubular member having a relatively high temperature coefficient of expansion, said tubular member affixed at one end to said second movable contact element and projecting longitudinall within said carbon pile resistance, a rod having a relatively low temperature coeiiicient of expansion, said rod having one end afiixed to the other end of said tubular member and said rod extending longicent the one end of said tubular member so that upon an increase in temperature expansion of said tubular member relative to said rod may efiect movement of said second contact element so as to compensate for expansion of the carbon pile resistance caused by the increase in temperature.

5. An electrical regulator, comprising, in combination, a housing, a tubular insulating member mounted in said housing, a plurality of carbon discs positioned in said tubular member to provide a carbon pile, a pair of contact elements positioned in said tubular member at opposite ends of said carbon pile, an electromagnet, an armature in operative relation to said electromagnet, a main spring to bias said armature in opposition to said electromagnet, a button carried by one of said contact elements, an element of said armature, said carbon pile includes a plurality of hollow carbon discs, a second tubular member having a relatively high temperature coeificient of expansion, said second tubular memher afiixed at one end to the other movable contact element and projecting longitudinally into said hollow carbon discs, a rod having a relatively low temperature coefiicient' of expansion, said rod havin one end afiixed to the other end of said second tubular member and said rod extending longitudinally through said second tubular member, another end of said rod connected to said housing so that upon an increase in temperature elongation of said second tubular member relative to said rod may efiect a movement of the said other contact element so as to compensate for expansion of the carbon discs caused by the increase in temperature.

6. The combination comprising, a first tubular insulating member, a carbon pile having a plurality of hollow carbon discs positioned in said first tubular member, a pair of contact elements positioned in said first tubular member at opposite ends of said carbon pile, a second tubular member having a relatively high temperature coefiicient of expansion, said second tubular member affixed at one end to one of said movable contact elements and projecting longitudinally into said hollow carbon discs, a rod having a relativelylow temperature coefiicient of expansion, said rod having one end aflixed to the other end of said second tubular member and said rod extending longitudinally through said second tubular member, another end of said rod fixedly mounted so that upon an increase in temperature elongation of said second tubular member relative to said rod may effect a movement of the said one contact element so as to compensate for expansion of the carbon discs caused by the increase in temperature.

WILLIAM G. NEILD.

REFERENCES CITED She following references are of record in the e m of this patent:

UNITED STATES PATENTS 

